LOS ANGELES — Responding to the state’s worsening water shortage, the Metropolitan Water District on Monday announced that it would cut water supplies to Southern California agriculture by 30 percent and that local residents can expect their bills to rise by 10 percent or more.

The moves come as Southern California is facing both a cut in water supplies from Northern California and is dealing with a major drought locally.

MWD General Manager Jeffrey Kightlinger said that if the record dry spell continues into this winter, local agencies would have to consider mandatory rationing.

The fate of an endangered fish in the Sacramento-San Joaquin Delta is expected to lead to a federal court-imposed cutback of almost 30 percent on water supplies to Southern California, and the Colorado River is showing the effects of eight years of drought.